US3643125A - Deflection system for triad-beam cathode-ray tube utilizing a toroid-type deflection yoke - Google Patents

Deflection system for triad-beam cathode-ray tube utilizing a toroid-type deflection yoke Download PDF

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US3643125A
US3643125A US841935A US3643125DA US3643125A US 3643125 A US3643125 A US 3643125A US 841935 A US841935 A US 841935A US 3643125D A US3643125D A US 3643125DA US 3643125 A US3643125 A US 3643125A
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horizontal
vertical
deflection
windings
ray tube
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US841935A
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Charies Edward Torsch
Joseph Edward Thomas
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GTE Sylvania Inc
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Sylvania Electric Products Inc
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/12—Picture reproducers
    • H04N9/16—Picture reproducers using cathode ray tubes
    • H04N9/28—Arrangements for convergence or focusing
    • H04N9/285—Arrangements for convergence or focusing using quadrupole lenses
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/70—Arrangements for deflecting ray or beam
    • H01J29/72—Arrangements for deflecting ray or beam along one straight line or along two perpendicular straight lines
    • H01J29/76—Deflecting by magnetic fields only
    • H01J29/764—Deflecting by magnetic fields only using toroidal windings
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/4902—Electromagnet, transformer or inductor
    • Y10T29/49071—Electromagnet, transformer or inductor by winding or coiling

Definitions

  • a cathode-ray tube deflection system includes a triad-type cathode-ray tube and a toroid-type deflection yoke having horizontal and vertical axes with first and second horizontal windings symmetrical to the horizontal axis in mirror image of one another about the vertical axis and first and second vertical winding symmetrical to the vertical axis in mirror image of one another about the horizontal axis and said first and second horizontal and vertical windings each including a flux altering means for enhancing vertical convergence of horizontal trace lines.
  • the deflection yoke is formed by a process wherein a core of magnetic material is wrapped with wire turns applied in toroidal fashion to form first and second horizontal windings and first and second vertical windings advanced in opposite circumferential direction to form a mirror image relationship. Also, ringing is inhibited by circuitry wherein a specific terminal of each of the horizontal and the vertical windings associated with the start of electron beam scanning of the cathode-ray tube is connected to a potential reference level while the other extremities of the horizontal and vertical windings are connected to a source of deflection signals whereby undesired distortions appearing on the trace lines of the viewing screen are minimized.
  • Cathode ray tube deflection systems normally include a cathode ray tube and an associated deflection yoke.v The cathode ray tube has a viewing screen which is impinged by one or more electron beams to provide a so-called scan raster and the deflection yoke creates a magnetic field of altering strength and polarity which causes the electron beam to scan the viewing screen to effect the scan raster.
  • the most common type of deflection yoke is the so-called saddle yoke.
  • a pair of horizontal deflection windings are mounted on the top and bottom respectively of the cathode ray tube to produce a magnetic field parallel to a vertical. axis.
  • a pair of vertical deflection windings are mounted on opposite sides of the cathode ray tube to effect a magnetic field parallel .to a horizontal axis.
  • an'in-line gun type of cathode ray tube evolves special problems which require a specific form of deflection yoke as well as a special form of convergence apparatus.
  • the deflection yoke apparatus provides a substantially straight-sided; scan raster unsuitable to the normally employed convergence and pin cushion circuitry common to triad-gun deflection systems, but rather adapted to size correction apparatus foreign to triad-gun systems.
  • present day NTSC color television receivers employ horizontal scanning by the electron beam at a rate of about 15,734 cycles per second with the electron beam scanning from left to right of the viewing screen, as seen by an observer, and rapidly retracing or returning to repeat the scan cycle. Also, the electron beam is advanced in a vertical direction from the top to the bottom of the cathode ray tube at a rate of about 60 cycles per second and rapidly returned to repeat the cycle.
  • circuitry is complex as well as expensive in components and assembly time and skill. Moreover, the circuit complexity reduces reliability while adding undesired, bulk and cost.
  • Still another object of the invention is to provide a toroidally wounddeflection yoke and a deflection circuit arrangement suitable forreplacement of the well-known saddle" yoke and deflection circuit arrangement employed in triad-gun type cathode ray tube systems.
  • a deflection yoke having a substantially circular core of magnetic material with first and. second, horizontal deflection windings toroidally wound thereon in mirror image of one another and oppositely disposed about a vertical axis.
  • the deflection yoke is fabricated by a process wherein a circular core is selected and wrappedwith toroidal wire turns to provide bank-wound wire groups which are intermittently spaced along the circumference of the core to provide a winding.
  • a deflection circuit arrangement for minimizing ringing currents in a deflection yoke includes a circuit means coupling one of a pair of series connected deflection windings associated with the start of electron beam scanning to a potential reference level and theother deflection winding to a deflection signal source.
  • FIG. 1 is a cross-sectional elevation of a cathode ray tube and associated toroidal deflection yoke
  • FIG. 2 is a screen-end view diagram of the winding distribu tionof the exterior wires of a toroidal yoke embodiment of the invention
  • FIG. 3 is a planar view illustrating the form of a pair of horizontal windings
  • FIG. 4 is an elevation view illustrating the form of a pair of vertical windings
  • FIGS. 5, 6 and 7 illustrate a cathode ray tube raster as observed by a viewer
  • FIGS. 8 and 9 are graphical representations of the horizontal deflection windings
  • FIG. is a graphical representation of a vertical deflection winding
  • FIG. 11 is an illustration, in block and schematic form, of a television receiver and associated deflection circuit arrangement for a cathode ray tube.
  • FIG. 12 is a schematic illustration of the winding of a toroidal deflection yoke and associated deflection circuit arrangement.
  • FIG. 1 illustrates a typical cathode ray tube deflection system including a triad-type cathode ray tube 5, a deflection yoke 7, and a convergence coil 9.
  • the cathode ray tube 5 includes 'a viewing screen 11 which is impinged by one or more electron beams 13 derived from one or more electron guns 15.
  • a convergence coil 9 is normally disposed rearwardly, as viewed by a cathode ray tube observer, of the viewing screen 11 and of the deflection yoke 7. This convergence coil 9 serves to effect convergence of the plurality of electron beams 13 at or near the surface of the viewing screen 11 of the cathode ray tube 5.
  • the deflection yoke 7 is affixed to the cathode ray tube 5 and located rearwardly of the viewing screen 11. This deflection yoke 7 is generally operable in a manner wellknown in the art to effect deflection of the electron beams 13 in both horizontal and vertical directions. Moreover, the deflection yoke 7, as employed in all known present day television receivers, causes electron beam scanning which progresses from left to right and top to bottom of the viewing screen 11.
  • the deflection yoke 7 is of the toroidal type having a substantially circular core 16 of a magnetic material having a relatively high permeability factor, 100 or more for instance, and a plurality. of windings of wire turns 17 wrapped in toroidal fashion on the circular core 16.
  • wire turns 17 and toroidal windings reference is made to the schematic illustration of FIG. 2.
  • a preferred wire configuration form includes a substantially circular core 16 of magnetic material supporting a plurality of toroidal wrapped wire turns. For clarity, only those turns in abutting relationship to the outer surface of the core 16 are illustrated. Also, a preferred wire configuration form includes at least one of such features as interlaced deflection windings, sawtooth"-wound deflection windings, mirror image deflection windings, intermittent bank-wound deflection windings, deflection windings having a flux altering means, intermittent bank-wound deflection windings having added turns, and deflection windings affixed by a process which includes advancement in opposite circumferential directions. Moreover, the above-mentioned features will be explained hereinafter.
  • the wire configuration of FIG. 2 includes a horizontal axis H-H' and a vertical axis designated V-V'.
  • the wire configuration and windings 19 and 21 of FIG. 2 are illustrated in the same positional location as they would appear to a viewer of the display screen 11 of the cathode ray tube 5 of FIG. 1, with the deflection yoke 7 attached thereto.
  • each of the horizontal deflection windings 19 and 21 is not only substantially symmetrical with respect to the horizontal axis H-H' but also in substantially mirror image relationship on opposite sides thereof. Moreover, each of the horizontal deflection windings 19 and 21 includes a flux altering means 23 and 25 respectively, centrally disposed about the horizontal axis I-I-H' which, in this instance, is illustrated as a winding gap. Obviously, short-circuited turns, shielded turns, and similar techniques for altering a flux pattern would be equally appropriate.
  • each of the horizontal deflection windings 19 and 21 includes a plurality of wire groups or groups of wire turns in intermittent circumferential spaced relationship about the circular core 16.
  • Each of these groups of wire turns has a cen trally located force of magnetic influence and is preferably in the form of an intermittent bank winding wherein a first layer of turns includes at least one pair of adjacent turns and a second layer of turns includes a wire turn contacting and supported by the pair of adjacent turns of the first layer of turns. Should the wire group include more than a single pair of adjacent turns in the first layer of turns, the second layer of turns would include a wire turn contacting and supported by each pair of turns of the first layer.
  • These particular intermittent bank-wound horizontal deflection windings l9 and 21 each include added turns 27/28 and 29/30 respectively, disposed on opposite sides of the flux altering means 23 and 25. Moreover, these added turns 27/28 and 29/30 are preferably disposed in substantially similar but not necessarily identical circumferential spaced relationship to the flux altering means 23 and 25, and serve to enhance electron beam convergence, as will be explained hereinafter.
  • first and second horizontal deflection windings 19 and 21 are preferably, not necessarily, in complete mirror image relationship to one another about the vertical axis V-V.
  • first horizontal deflection winding 19 and the second horizontal deflection winding 21 are affixed in reversed progression to effect the above-described mirror image relationship about the vertical axis V-V, as observed on the exterior surface of the core member 16.
  • the above-mentioned mirror image relationship between the first and second deflection windings is preferably, not necessarily, an identical relationship.
  • the circumferential spacing of the added turns 27 and 28 of the first deflection winding 19 with respect to the horizontal axis H-H' differs from the circumferential spacing of the added turns 29 and 30 of the second deflection winding 21.
  • the abovedescribed mirror image relationship is effected except for this slight deviation of the added turns 27 and 28 and 29 and 30.
  • each vertical deflection winding 31 and 33 is symmetrical to the vertical axis V-V' and disposed in mirror image relationship about the horizontal axis H-H'. Also, each vertical deflection winding 31 and 33 includes a flux altering means 35 and 37 which is also symmetrically disposed about the vertical axis V-V.
  • each of the vertical deflection windings 31 and 33 is in the form of intermittent circumferentially spaced wire groups.
  • the vertical deflection windings 31 and 33 are in the form of intermittent spaced wire groups which are electrically connected in a sawtooth manner.
  • the first layer of turns of the total winding are serially connected and advanced in one circumferential direction.
  • the second layer of turns is applied to the first layer and advanced in the same circumferential direction.
  • first vertical deflection winding 31 and the second vertical deflection winding 33 are affixed to the core member 16 in reversed progression.
  • first and second vertical deflection windings 31 and 33 provide a mirror image relationship with respect to one another about a horizontal axis H-H as observed from the exterior surface of the core member 16, from either left or right side of the yoke.
  • a toroid defection yoke having interleaved first and second horizontal and first and second vertical deflection windings, l9 and 21 and 31 and 33.
  • the horizontal deflection windings 19 and 21 are each in vertical symmetrical relationship about the horizontal axis H-H' and in substantial mirror image relationship to one another about the vertical axis V-V'.
  • each of the horizontal deflection windings 19 and 21 is in bank-wound form and respectively includes a flux altering means 23 and 25 and added turns 27/28 and 29/30 symmetrically disposed about the horizontal axis H-l-l'.
  • the vertical deflection windings 31 and 33 are horizontally symmetrical about the vertical axis V-V' and in mirror image of one another about the horizontal axis H-H'. Moreover, the vertical deflection windings 31 and 33 are of sawtooth-connected form and respectively include a flux altering means 35 and 37. '1
  • a substantially circular core 16 of magnetic material having a horizontal and a vertical axis is selected. Wire turns are wrapped in toroidal fashion on opposite sides of the horizontal axis 11-11 of the core 16 and advanced in opposite circumferential directions to provide first and second vertical deflection windings 31 and 33. Also, wire turns are wrapped in toroidal fashion on opposite sides of the vertical axis V-V of the core 16 and advanced in opposite circumferential directions to provide first and second horizontal deflection windings 19 and 21. Moreover, the windings are circumferentially spaced such that interleaving of the vertical and horizontal windings is effected.
  • a preferred process for fabricating a toroid-type deflection yoke of the type illustrated in FIG. 2 includes selecting a substantially circular core 16 of a magnetic material. Then, the first layer of turns of the vertical deflection windings 31 and 33 are wrapped in toroidal fashion about the circular core 16. This first layer of turns includes intermittent circumferentially spaced pairs of wire turns which are advanced in opposite circumferential directions on the core 16 and disposed on opposite sides of the horizontal axis of the core 16. Thus the first layer of turns of both the first and second vertical deflection windings 31 and 33 define intermittent circumferential spaces along the core 16.
  • first and second horizontal deflection windings 19 and 21 are applied to the core 16 in interleaved relationship with the first and second vertical deflection windings 31 and 33.
  • the first and second horizontal deflection windings l9 and 21 are formed by wrapping wire turns in toroidal fashion about the core 16 in the intermittent circumferential spaces defined by the first layer of wire turns of the first and second vertical deflection windings 31 and 33.
  • the first and second horizontal deflection windings 19 and 21 are oppositely disposed with respect to the vertical axis V-V and are advanced in opposite circumferential directions.
  • At least one pair of toroidal wrapped wire turns is affixed to the core 16 within a space defined by the vertical deflection windings 31 and 33. Then, a toroidal wrapped turn of a second layer contacts and is supported by the pair of wire turns of the first layer to provide a wire group. Also, the wire turns of the first and second layers are serially connected to minimize the potential difference therebetween which, in turn, minimizes insulation requirements.
  • the winding then advances to the following space defined by the first layer of the vertical deflection windings 31 and 33.
  • a plurality of pairs of turns may be affixed to the core 16 with the second layer of turns including a first turn supported by 'the first pair of turns of the first layer and following turns advancing in the same circumferential direction as the first layer of turns with a second layer turn contracting and supported by each advancing pair of turns of the first layer.
  • each of the horizontal deflection windings 19 and 21 is of the so-called bank-wound form wherein each turn of a second layer of turns is supported by a pair of turns of a first layer of turns. Also, the turns of the first and second layers of turns are advanced in the same circumferential direction. Moreover, the wire turns of the vertical deflection windings 31 and 33 serve to 'c'onfine the wire groups of the horizontal deflection windings 19 and 21 to a restricted space preventing undesired distortion and spreading of the first layer of turns by the force exerted thereon by the second layer of turns.
  • a second layer of toroidal wrapped wire turns is applied to the vertical deflection windings 31 and 33.
  • This second layer of turns starts in the same location and advances in the same direction as the first layer of turns of each of the vertical deflection windings 31 and 33.
  • the final turn of the first layer of turns of each of the vertical deflection windings 31 and 33 is connected electrically to the first turn of the second layer of turns.
  • This type connection is normally referred to as a sawtooth connection whereby the potential difference intermediate adjacent turns of the first and second layers is substantially constant throughout the total winding.
  • first and second vertical deflection windings 31 and 33 are affixed to the core 16 by applying a first layer of spaced turns advanced in opposite circumferential direction.
  • the first and second horizontal deflection windings 19 and 21 are interleaved with the vertical deflection windings 31 and 33 within the spaces provided by the first layer thereof.
  • These horizontal deflection windings 19 and 21 are of a bank-wound form with first and second layers of wire turns forming wire groups and the wire turns and wire groups serially connected.
  • the second layer of turns of the vertical deflection windings 31 and 33 are applied to the first layer to form wire groups advancing in opposite circumferential directions and electrically connected in a sawtooth connection.
  • the observer of the viewing screen 11 of a triad-gun type color cathode ray tube 5 tended to see a substantially straight-sided raster, illus trated in FIG. 5.
  • the raster has what is commonly referred to as a reverse red trapazoid wherein the red and green traces have opposing slopes with the separation of the green traces at a minimum to the right of the viewing screen 11 as observed by a viewer.
  • convergence of the traces of a color receiver wherein the abovementioned reverse red trapazoid" is present was most difficult, if not impossible, with convergence circuitry normally available in present-day television receivers utilizing triad-gun type cathode ray tubes.
  • the pincushion circuitry readily available in triad-gun type color television receivers is employed, in the usual manner, to effect pincushion correction and convergence of the red and green traces of the electron beams of a color cathode ray tube. Therefore, the toroid deflection yoke 7 is employable with a television receiver having the usual triadgun type cathode ray tube, pincushion correction circuitry and convergence apparatus to provide a desired color image display.
  • the specific embodiment of a toroid-wound deflection yoke illustrated in FIG. 2 includes the added turns 27 and 28 of the first or left horizontal deflection winding 19, as well as the added turns 29 and 30 of the second or right horizontal deflection winding 21. Also, the added turns 27 and 28 are at a slightly different circum ferential spacing from the horizontal axis HH' than the added turns 29 and 30 due to the effect of the earths magnetic field in the Northern Hemisphere.
  • FIGS. 8 and 9 will serve to illustrate the winding distribution of the horizontal deflection windings 19 and 21 in a quadrant to the left and right of the vertical-axis V-V'.
  • the X-axis represents the angular degrees 6 from the horizontal axis H-H
  • the Y-axis numerals W represent the rim order intercept of a wire group with respect to the horizontal axis H-H'.
  • Each of the wire groups W is considered to be a unit, three toroid turns in this instance, having a central acting vector unit of force insofar as the magnetic effect and angular degrees are concerned.
  • the wire and turn content of each of the wire groups W is varied to provide variations in impedance and may include one or a number of turns depending upon the impedance value desired.
  • the curve is representative of the upper left quadrant as well as the lower left quadrant of the first or left horizontal deflection winding 19 since the winding is substantially symmetrical with respect to the horizontal axis H-H'.
  • This curve of FIG. 8 maybe represented by the following formulation:
  • FIG. 10 will serve to illustrate the winding distribution of the vertical deflection windings 31 and 33.
  • the X-axis represents the angular degrees (1) from the vertical axis V-V' while the Y-axis numerals represent the rim-order intercept of a wire group W with respect to the vertical axis V-V'.
  • each of the wire groups W represent a central acting vector of force.
  • H6 10 will serve to represent quadrants to the left and right of the vertical axis V-V', as well as above and below the horizontal axis H-H', since the windings are symmetrical.
  • toroid-wound deflection yokes have been fabricated wherein both the first and second horizontal deflection windings 19 and 21 and the first and second vertical deflection windings 31 and 33 are symmetrical.
  • the formulation Wr representa tive of the right horizontal deflection winding 21 is also employed in fabricating the left horizontal deflection winding 19.
  • satisfactory results have been obtained when the degrees 0 from the horizontal axis H-H' and the degrees d from the vertical axis V-V' to the center of influence of the wire group W are not varied from the above formulations by more than about three degrees (3).
  • FIG. 11 illustrates a typical television receiver employing the usual antenna 38 whereat transmitted television signals are intercepted and applied to a signal receiver 39.
  • the signal receiver 39 includes the usual RF and IF signal amplifier and detector stages and provides an output signal which is applied via an audio amplifier stage 40 to a loudspeaker 41.
  • Another output from the signal receiver 39 includes signals representative of both luminance and synchronizing information and is applied to a video amplifier stage 43.
  • One output signal available from the video amplifier stage 43 and representative of luminescence information is applied to a control electrode of a cathode ray tube 45.
  • Another output signal available from the video amplifier stage 43 and representative of synchronizing information is applied to a synchronizing separator stage 47.
  • signals representative of vertical and horizontal scan frequencies are derived and applied to vertical and horizontal deflection stages 49 and 51 respectively.
  • the vertical deflection stage 49 is coupled via an output transformer 53 to a pair of output terminals YY'- and one of the output terminals Y is AC coupled by a capacitor 54 to a potential reference level such as circuit ground. ln turn, the output terminals YY' are coupled to a pair of series connected vertical deflection coil windings, 55 and 57 associated with a cathode ray tube 45.
  • the horizontal deflection state 51 is coupled to a horizontal output transformer winding 59.
  • One end of the transformer winding 59 is coupled by way of a rectifier stage 61 to a high voltage electrode of the cathode ray tube 45 while the other end of the transformer winding 59 is coupled via a capacitor 68 to a DC potential source 8+.
  • a series connected damper stage 65 and alterable inductor 67, linearity control, shunted by a tuning capacitor are coupled intermediate a junction of the transformer winding 59 and the DC potential source B+.
  • a pair of series connected horizontal deflection coils 69 and 71 associated with the cathode ray tube 45 have one end thereof connected to a junction 73 of the transformer winding 59 and the other end coupled via the capacitor 63 to the DC potential source 8+ and to the transformer winding 59.
  • a capacitor 75 is shunted across the horizontal deflection coil 71 connected to the end of the transformer winding 59 via capacitors 63 and 68 and to the potential source B+.
  • a toroidal-wound deflection yoke is schematically illustrated in cooperation with a triad-type color cathode ray tube.
  • the neck portion 77 of a color cathode ray tube includes the triad of electron guns 79 and is surrounded by the toroid-wound deflection yoke 81.
  • the first or left horizontal deflection winding 71 is associated with the beginning of the usual left to right horizontal scanning of the cathode ray tube.
  • This winding 71 is AC coupled by a capacitor 63 to a DC potential source B+.
  • a capacitor 75 shunts the winding 71 and a second or right horizontal deflection winding 69 series connects the first horizontal deflection winding 71 to a horizontal deflection signal source, 73 of FIG. 11.
  • a portion of the transformer winding 59 is coupled by the storage boost capacitor 68 to the DC potential source B+.
  • a first or top vertical deflection winding 57 associated with the beginning of vertical scanning is AC coupled by a capacitor 54, to a potential reference level such as circuit ground.
  • the first vertical deflection winding 57 is series connected to a second vertical deflection winding 55 coupled to a vertical deflection signal source Y" ofFlG. 11.
  • first horizontal deflection winding 71 and the first or top vertical deflection winding 57 are concerned with the start of both horizontal and vertical scanning. Also, the previously mentioned opposing circumferential directions of advancement of the windings serves to effect neutralization of the electrostatic charging of the distributed capacitance between first and second vertical deflection windings 57 and S and the first and second horizontal deflection windings 71 and 69.
  • the mirror image relationship of the windings assists in neutralizing magnetic and electrostatic cross-induction between the horizontal windings 69 and 71 and the vertical windings 55 and 57.
  • This neutralization of electrostatic and magnetic cross-induction between horizontal and vertical winding is also aided by the substantially sawtooth connection of the vertical windings 57 and 55 as well as the intermittent bank-wound type connections of the horizontal windings 71 and 69.
  • the first horizontal deflection winding 71 most closely associated with the ringing" effect has one end thereof coupled via the capacitor 63 to a potential reference level 8+ with the other end closely associated with the grounded end of the vertical deflection winding 57.
  • the horizontal winding 71 and the vertical winding are interleaved which also assists in draining undesired energy from both the horizontal and vertical windings 71 and 57 associated with the start of both horizontal and vertical scan.
  • undesired energy drain of the horizontal deflection winding 71 is even further enhanced by the shunting capacitor 75.
  • the shunting capacitor 75 provides a rapid path for energy drain to the potential reference level 8+.
  • a deflection circuit arrangement for minimizing ringing currents comprising:
  • a toroid-wound deflection yoke associated with said color cathode ray tube, said yoke including a core of magnetic material having horizontal and vertical axes with serially connected first and second horizontal deflection windings and serially connected first and second vertical deflection windings, each of said first and second horizontal deflection windings being substantially centered about said horizontal axis and oppositely disposed about said verti cal axis of said core and each of said first and second vertical deflection windings being substantially centered about said vertical axis and oppositely disposed about said horizontal axis of said core with said first and second horizontal and vertical windings circumferentially interleaved;
  • circuit means coupling said first horizontal deflection winding associated with the start of electron beam scanning of said viewing screen to said potential source;
  • circuit arrangement of claim 1 including means coupling said first vertical deflection winding associated with the start of electron beam scanning of said viewing screen to said potential source and said second vertical deflection winding associated with the finish of electron beam scanning of said viewing screen to said vertical deflection signal source.
  • first and second vertical deflection windings each include first and second wire layers electrically connected by a sawtooth-type connection whereby the potential difference intermediate adjacent turns of said first and second layers is substantially constant.
  • each of said first and second horizontal deflection windings includes a flux altering means substantially centered about said horizontal axis.
  • each of said first and second vertical deflection windings includes a flux-altering means substantially centered about said vertical axis.

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Video Image Reproduction Devices For Color Tv Systems (AREA)
  • Details Of Television Scanning (AREA)

Abstract

A cathode-ray tube deflection system includes a triad-type cathode-ray tube and a toroid-type deflection yoke having horizontal and vertical axes with first and second horizontal windings symmetrical to the horizontal axis in mirror image of one another about the vertical axis and first and second vertical winding symmetrical to the vertical axis in mirror image of one another about the horizontal axis and said first and second horizontal and vertical windings each including a flux altering means for enhancing vertical convergence of horizontal trace lines. The deflection yoke is formed by a process wherein a core of magnetic material is wrapped with wire turns applied in toroidal fashion to form first and second horizontal windings and first and second vertical windings advanced in opposite circumferential direction to form a mirror image relationship. Also, ''''ringing'''' is inhibited by circuitry wherein a specific terminal of each of the horizontal and the vertical windings associated with the start of electron beam scanning of the cathode-ray tube is connected to a potential reference level while the other extremities of the horizontal and vertical windings are connected to a source of deflection signals whereby undesired distortions appearing on the trace lines of the viewing screen are minimized.

Description

United States Patent Torsch et al.
[ Feb. 15,1972
[54] DEFLECTION SYSTEM FOR TRIAD- BEAM CATHODE RAY TUBE UTILIZING A TOROID-TYPE DEFLECTION YOKE [72] Inventors: Charles Edward Torsch, Rochester; Joseph Edward Thomas, Batavia, both of NY.
[73] Assignee: Sylvania Electric Products Inc.
[22] Filed: July 15, 1969 [2]] Appl. No.: 841,935
Primary Examiner-Rodney D. Bennett, Jr.
Assistant Examiner-J. M. Potenza Attorney-Norman J. OMalley, Thomas H. Buflton and Donald R. Castle [57] ABSTRACT A cathode-ray tube deflection system includes a triad-type cathode-ray tube and a toroid-type deflection yoke having horizontal and vertical axes with first and second horizontal windings symmetrical to the horizontal axis in mirror image of one another about the vertical axis and first and second vertical winding symmetrical to the vertical axis in mirror image of one another about the horizontal axis and said first and second horizontal and vertical windings each including a flux altering means for enhancing vertical convergence of horizontal trace lines. The deflection yoke is formed by a process wherein a core of magnetic material is wrapped with wire turns applied in toroidal fashion to form first and second horizontal windings and first and second vertical windings advanced in opposite circumferential direction to form a mirror image relationship. Also, ringing is inhibited by circuitry wherein a specific terminal of each of the horizontal and the vertical windings associated with the start of electron beam scanning of the cathode-ray tube is connected to a potential reference level while the other extremities of the horizontal and vertical windings are connected to a source of deflection signals whereby undesired distortions appearing on the trace lines of the viewing screen are minimized.
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A I4 58/91 I2 IO f 8 J 0 IO 20 3O 4O 5O 6O 7O 8O DEGREES FROM HORIZONTAL AXIS IN VEN TORS JOSEPH E. THOMAS 81 CHARLES E-TORSCH VERTICAL COIL W- GROUP INTERCEPT PATENTEDFEB 1 5 I972 v SHEET 5 [IF 6 l4 12 f IO b Cfi 8 j 0 20 3o 40 so so DEGREES FROM VERTICAL AXIS INVENTORS JOSEPH E-THOMAS 8. By CHARLES E.TORSCH ATTORNEY PAIENTEDFEB 15 m2 3.643.125
sum 5 or 6 VIDEO AMPLIFIER VERTICAL DEFLECTION DEFLECTION AUDIO AMPLIFIER L HORIZONTAL INVENTORS JOSEPH E.THOMAS 8. Y CHARLES E.TORSCH ATTORNEY SIGNAL RECEIVER DEFLECTION SYSTEM FOR TRIAD-BEAM CATHODE- RAY TUBE UTILIZING A TOROID-TYPE DEFLECTION YOKE BACKGROUND OF THE INVENTION Cathode ray tube deflection systems normally include a cathode ray tube and an associated deflection yoke.v The cathode ray tube has a viewing screen which is impinged by one or more electron beams to provide a so-called scan raster and the deflection yoke creates a magnetic field of altering strength and polarity which causes the electron beam to scan the viewing screen to effect the scan raster.
In present day television receivers and especially in receivers employing a cathode ray tube wherein the electron guns and phosphors of the viewing screen are of a triad arrangement, the most common type of deflection yoke is the so-called saddle yoke. In the saddle" yoke construction, a pair of horizontal deflection windings are mounted on the top and bottom respectively of the cathode ray tube to produce a magnetic field parallel to a vertical. axis. Also, a pair of vertical deflection windings are mounted on opposite sides of the cathode ray tube to effect a magnetic field parallel .to a horizontal axis.
Although such devices have been and stillare widely employed in triad-type cathode ray tube deflection systems, it has.
emanating from a triad gun arrangement are converged to.
provide a scan raster on a viewing screen of the cathode ray tube-"Moreover, well-known pin cushion correction circuitry employed in all known triad-type deflection systems is utilized to effect a substantially straight-sided raster.
Although the above-mentioned triad-type deflection systems employing a saddle yoke do leave something to be desired, the only known attempt to overcome the above-mentioned problems is the provision of a so-called in-line deflection system. Therein, a cathode ray tube having a plurality. of electron guns arrayed in a single plane is employed with a socalled toroid" type deflection yoke.
As set forth in US. Pat. No. 2,925,542 issued to R. B. Gethmann on Feb. 16, I960 and US. Pat. No. 3,430,099 issued to R. B. Ashley on Feb. 25, 1969, an'in-line gun type of cathode ray tube evolves special problems which require a specific form of deflection yoke as well as a special form of convergence apparatus. As set forth therein, the deflection yoke apparatus provides a substantially straight-sided; scan raster unsuitable to the normally employed convergence and pin cushion circuitry common to triad-gun deflection systems, but rather adapted to size correction apparatus foreign to triad-gun systems.
Additionally, present day NTSC color television receivers employ horizontal scanning by the electron beam at a rate of about 15,734 cycles per second with the electron beam scanning from left to right of the viewing screen, as seen by an observer, and rapidly retracing or returning to repeat the scan cycle. Also, the electron beam is advanced in a vertical direction from the top to the bottom of the cathode ray tube at a rate of about 60 cycles per second and rapidly returned to repeat the cycle.
As is well known, the abrupt change in value of a potential applied to the deflection windings to effect the rapid retrace of the electron beam and initiation of a following scan line causes the development of oscillations or spurious ringing in the windings of the yoke, This undesired ringing" usually continues after the scanning period of the electron beam is started and appears as an undesired intensity variation or distortion at the left-hand portion of the viewing screen raster as observed by a viewer.
In order to minimize this undesired distortion due to ringing", it has been a common practice to employ circuitry such as set forth in US. Pat. No. 2,869,030 issued to M. Deranian et al. on Jan. 13, 1959. Therein, a pair of horizontal deflection windings of the so-called saddle" type are series connected, a pair of series connected capacitors'of substantially equal value are shunted across the series connected windings, a resistor couples the junction of the series connected capacitors to the junction of the series connected deflection windings, one of the windings is coupled to a deflection signal source and the other winding to an AC potential reference level, and a capacitor is shunt connected across the winding coupled to the deflection signal source. Moreover, vertical saddle" windings are usually shunted by resistors to damp the capacitively coupled charge flow from the horizontal coils during and after horizontal rctrace.
Obviously, the above-mentioned circuitry is complex as well as expensive in components and assembly time and skill. Moreover, the circuit complexity reduces reliability while adding undesired, bulk and cost.
OBJECTS AND SUMMARY OF THE INVENTION It is an object of the present invention to provide an enhanced cathode ray tube deflection system. Another object of the invention is to provide an improved deflection yoke applicable to a television receiver deflection system. Still another object of the invention is to provide an enhanced process for fabricating improved deflection yokes for cathode ray tube deflection systems. A .further object of the invention is to provide an improved deflection circuit arrangement for a television receiver. A still further object of the invention is to provide an improved process for fabricating an improved deflection yoke. for use in an improved deflection.circuitry arrangement. Still another object of the invention is to provide a toroidally wounddeflection yoke and a deflection circuit arrangement suitable forreplacement of the well-known saddle" yoke and deflection circuit arrangement employed in triad-gun type cathode ray tube systems.
These and other objects, advantages and capabilities are achieved-in one aspect of the invention by a deflection yoke having a substantially circular core of magnetic material with first and. second, horizontal deflection windings toroidally wound thereon in mirror image of one another and oppositely disposed about a vertical axis. The deflection yoke is fabricated by a process wherein a circular core is selected and wrappedwith toroidal wire turns to provide bank-wound wire groups which are intermittently spaced along the circumference of the core to provide a winding. Also, a deflection circuit arrangement for minimizing ringing currents in a deflection yoke includes a circuit means coupling one of a pair of series connected deflection windings associated with the start of electron beam scanning to a potential reference level and theother deflection winding to a deflection signal source.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional elevation of a cathode ray tube and associated toroidal deflection yoke;
FIG. 2 is a screen-end view diagram of the winding distribu tionof the exterior wires of a toroidal yoke embodiment of the invention;
FIG. 3 is a planar view illustrating the form of a pair of horizontal windings;-
FIG. 4 is an elevation view illustrating the form of a pair of vertical windings;
FIGS. 5, 6 and 7 illustrate a cathode ray tube raster as observed by a viewer;
FIGS. 8 and 9 are graphical representations of the horizontal deflection windings;
FIG. is a graphical representation of a vertical deflection winding;
FIG. 11 is an illustration, in block and schematic form, of a television receiver and associated deflection circuit arrangement for a cathode ray tube; and
FIG. 12 is a schematic illustration of the winding of a toroidal deflection yoke and associated deflection circuit arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENT For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in conjunction with the accompanying drawings.
Referring to the drawings, FIG. 1 illustrates a typical cathode ray tube deflection system including a triad-type cathode ray tube 5, a deflection yoke 7, and a convergence coil 9. The cathode ray tube 5 includes 'a viewing screen 11 which is impinged by one or more electron beams 13 derived from one or more electron guns 15.
In cathode ray tube systems wherein the cathode ray tube 5 includes a plurality of electron beams 13 derived from a plurality of electron guns 15, a convergence coil 9 is normally disposed rearwardly, as viewed by a cathode ray tube observer, of the viewing screen 11 and of the deflection yoke 7. This convergence coil 9 serves to effect convergence of the plurality of electron beams 13 at or near the surface of the viewing screen 11 of the cathode ray tube 5.
Also, the deflection yoke 7 is affixed to the cathode ray tube 5 and located rearwardly of the viewing screen 11. This deflection yoke 7 is generally operable in a manner wellknown in the art to effect deflection of the electron beams 13 in both horizontal and vertical directions. Moreover, the deflection yoke 7, as employed in all known present day television receivers, causes electron beam scanning which progresses from left to right and top to bottom of the viewing screen 11.
Further, the deflection yoke 7 is of the toroidal type having a substantially circular core 16 of a magnetic material having a relatively high permeability factor, 100 or more for instance, and a plurality. of windings of wire turns 17 wrapped in toroidal fashion on the circular core 16. As to the wire turns 17 and toroidal windings, reference is made to the schematic illustration of FIG. 2.
In FIG. 2, a preferred wire configuration form includes a substantially circular core 16 of magnetic material supporting a plurality of toroidal wrapped wire turns. For clarity, only those turns in abutting relationship to the outer surface of the core 16 are illustrated. Also, a preferred wire configuration form includes at least one of such features as interlaced deflection windings, sawtooth"-wound deflection windings, mirror image deflection windings, intermittent bank-wound deflection windings, deflection windings having a flux altering means, intermittent bank-wound deflection windings having added turns, and deflection windings affixed by a process which includes advancement in opposite circumferential directions. Moreover, the above-mentioned features will be explained hereinafter.
More specifically, the wire configuration of FIG. 2 includes a horizontal axis H-H' and a vertical axis designated V-V'. A first or left horizontal deflection winding 19, represented by blackened dots, is disposed to the left of the vertical axis V-V and a second or right horizontal deflection winding 21, represented by blackened dots, is disposed to the right of the vertical axis V-V. Moreover, the wire configuration and windings 19 and 21 of FIG. 2 are illustrated in the same positional location as they would appear to a viewer of the display screen 11 of the cathode ray tube 5 of FIG. 1, with the deflection yoke 7 attached thereto.
As can be seen, each of the horizontal deflection windings 19 and 21 is not only substantially symmetrical with respect to the horizontal axis H-H' but also in substantially mirror image relationship on opposite sides thereof. Moreover, each of the horizontal deflection windings 19 and 21 includes a flux altering means 23 and 25 respectively, centrally disposed about the horizontal axis I-I-H' which, in this instance, is illustrated as a winding gap. Obviously, short-circuited turns, shielded turns, and similar techniques for altering a flux pattern would be equally appropriate.
Also, each of the horizontal deflection windings 19 and 21 includes a plurality of wire groups or groups of wire turns in intermittent circumferential spaced relationship about the circular core 16. Each of these groups of wire turns has a cen trally located force of magnetic influence and is preferably in the form of an intermittent bank winding wherein a first layer of turns includes at least one pair of adjacent turns and a second layer of turns includes a wire turn contacting and supported by the pair of adjacent turns of the first layer of turns. Should the wire group include more than a single pair of adjacent turns in the first layer of turns, the second layer of turns would include a wire turn contacting and supported by each pair of turns of the first layer.
These particular intermittent bank-wound horizontal deflection windings l9 and 21 each include added turns 27/28 and 29/30 respectively, disposed on opposite sides of the flux altering means 23 and 25. Moreover, these added turns 27/28 and 29/30 are preferably disposed in substantially similar but not necessarily identical circumferential spaced relationship to the flux altering means 23 and 25, and serve to enhance electron beam convergence, as will be explained hereinafter.
Further, the first and second horizontal deflection windings 19 and 21 are preferably, not necessarily, in complete mirror image relationship to one another about the vertical axis V-V. As can readily be seen in the illustrative example of FIG. 3, the first horizontal deflection winding 19 and the second horizontal deflection winding 21 are affixed in reversed progression to effect the above-described mirror image relationship about the vertical axis V-V, as observed on the exterior surface of the core member 16.
Additionally, the above-mentioned mirror image relationship between the first and second deflection windings is preferably, not necessarily, an identical relationship. In this specific illustration, referring back to FIG. 2, the circumferential spacing of the added turns 27 and 28 of the first deflection winding 19 with respect to the horizontal axis H-H' differs from the circumferential spacing of the added turns 29 and 30 of the second deflection winding 21. Thus, the abovedescribed mirror image relationship is effected except for this slight deviation of the added turns 27 and 28 and 29 and 30.
Interleaved with the first and second horizontal deflection windings l9 and 21 and symmetrically disposed about the vertical axis V-V is a first or top vertical deflection winding 31 and a bottom or second vertical deflection winding 33, both represented by white circles in the illustration of FIG. 2. Each of these vertical deflection windings 31 and 33 is symmetrical to the vertical axis V-V' and disposed in mirror image relationship about the horizontal axis H-H'. Also, each vertical deflection winding 31 and 33 includes a flux altering means 35 and 37 which is also symmetrically disposed about the vertical axis V-V.
As was previously explained with respect to the horizontal deflection windings l9 and 21, each of the vertical deflection windings 31 and 33 is in the form of intermittent circumferentially spaced wire groups. However, the vertical deflection windings 31 and 33 are in the form of intermittent spaced wire groups which are electrically connected in a sawtooth manner. Therein, the first layer of turns of the total winding are serially connected and advanced in one circumferential direction. The second layer of turns is applied to the first layer and advanced in the same circumferential direction. As a result, the potential difference between adjacent turns of the first and second layers is more nearly constant.
Also, as can be readily seen in the illustrative example of FIG. 4, the first vertical deflection winding 31 and the second vertical deflection winding 33 are affixed to the core member 16 in reversed progression. In this manner, the first and second vertical deflection windings 31 and 33 provide a mirror image relationship with respect to one another about a horizontal axis H-H as observed from the exterior surface of the core member 16, from either left or right side of the yoke.
Thus, there has been provided a toroid defection yoke having interleaved first and second horizontal and first and second vertical deflection windings, l9 and 21 and 31 and 33. The horizontal deflection windings 19 and 21 are each in vertical symmetrical relationship about the horizontal axis H-H' and in substantial mirror image relationship to one another about the vertical axis V-V'. Also, each of the horizontal deflection windings 19 and 21 is in bank-wound form and respectively includes a flux altering means 23 and 25 and added turns 27/28 and 29/30 symmetrically disposed about the horizontal axis H-l-l'.
Similarly, the vertical deflection windings 31 and 33 are horizontally symmetrical about the vertical axis V-V' and in mirror image of one another about the horizontal axis H-H'. Moreover, the vertical deflection windings 31 and 33 are of sawtooth-connected form and respectively include a flux altering means 35 and 37. '1
As to the fabrication of a toroid type deflection yoke a substantially circular core 16 of magnetic material having a horizontal and a vertical axis is selected. Wire turns are wrapped in toroidal fashion on opposite sides of the horizontal axis 11-11 of the core 16 and advanced in opposite circumferential directions to provide first and second vertical deflection windings 31 and 33. Also, wire turns are wrapped in toroidal fashion on opposite sides of the vertical axis V-V of the core 16 and advanced in opposite circumferential directions to provide first and second horizontal deflection windings 19 and 21. Moreover, the windings are circumferentially spaced such that interleaving of the vertical and horizontal windings is effected.
More specifically, a preferred process for fabricating a toroid-type deflection yoke of the type illustrated in FIG. 2 includes selecting a substantially circular core 16 of a magnetic material. Then, the first layer of turns of the vertical deflection windings 31 and 33 are wrapped in toroidal fashion about the circular core 16. This first layer of turns includes intermittent circumferentially spaced pairs of wire turns which are advanced in opposite circumferential directions on the core 16 and disposed on opposite sides of the horizontal axis of the core 16. Thus the first layer of turns of both the first and second vertical deflection windings 31 and 33 define intermittent circumferential spaces along the core 16.
Following, the first and second horizontal deflection windings 19 and 21 are applied to the core 16 in interleaved relationship with the first and second vertical deflection windings 31 and 33. The first and second horizontal deflection windings l9 and 21 are formed by wrapping wire turns in toroidal fashion about the core 16 in the intermittent circumferential spaces defined by the first layer of wire turns of the first and second vertical deflection windings 31 and 33. Moreover, the first and second horizontal deflection windings 19 and 21 are oppositely disposed with respect to the vertical axis V-V and are advanced in opposite circumferential directions.
In the actual application of one of the horizontal deflection windings 19 and 21, at least one pair of toroidal wrapped wire turns is affixed to the core 16 within a space defined by the vertical deflection windings 31 and 33. Then, a toroidal wrapped turn of a second layer contacts and is supported by the pair of wire turns of the first layer to provide a wire group. Also, the wire turns of the first and second layers are serially connected to minimize the potential difference therebetween which, in turn, minimizes insulation requirements.
Further, the winding then advances to the following space defined by the first layer of the vertical deflection windings 31 and 33. Moreover, a plurality of pairs of turns may be affixed to the core 16 with the second layer of turns including a first turn supported by 'the first pair of turns of the first layer and following turns advancing in the same circumferential direction as the first layer of turns with a second layer turn contracting and supported by each advancing pair of turns of the first layer.
Thus, each of the horizontal deflection windings 19 and 21 is of the so-called bank-wound form wherein each turn of a second layer of turns is supported by a pair of turns of a first layer of turns. Also, the turns of the first and second layers of turns are advanced in the same circumferential direction. Moreover, the wire turns of the vertical deflection windings 31 and 33 serve to 'c'onfine the wire groups of the horizontal deflection windings 19 and 21 to a restricted space preventing undesired distortion and spreading of the first layer of turns by the force exerted thereon by the second layer of turns.
Following, a second layer of toroidal wrapped wire turns is applied to the vertical deflection windings 31 and 33. This second layer of turns starts in the same location and advances in the same direction as the first layer of turns of each of the vertical deflection windings 31 and 33. Also, the final turn of the first layer of turns of each of the vertical deflection windings 31 and 33 is connected electrically to the first turn of the second layer of turns. This type connection is normally referred to as a sawtooth connection whereby the potential difference intermediate adjacent turns of the first and second layers is substantially constant throughout the total winding.
Thus, the first and second vertical deflection windings 31 and 33 are affixed to the core 16 by applying a first layer of spaced turns advanced in opposite circumferential direction. The first and second horizontal deflection windings 19 and 21 are interleaved with the vertical deflection windings 31 and 33 within the spaces provided by the first layer thereof. These horizontal deflection windings 19 and 21 are of a bank-wound form with first and second layers of wire turns forming wire groups and the wire turns and wire groups serially connected.
Then, the second layer of turns of the vertical deflection windings 31 and 33 are applied to the first layer to form wire groups advancing in opposite circumferential directions and electrically connected in a sawtooth connection.
As to operation of a toroidal-wound deflection yoke 7 in conjunction with a triad-type cathode ray tube 5, it may first be assumed that the flux altering means 23 and 25 of the first and second horizontal deflection windings 19 and 21 are omitted, aswell as the flux altering means 35 and 37 of the first and second vertical deflection windings 31 and 33. Also, it is assumed that the added turn pairs 27/28 and 29/30 have not been included in the first and second horizontal deflection windings 19 and 21.
Under these conditions, it was found that the observer of the viewing screen 11 of a triad-gun type color cathode ray tube 5 tended to see a substantially straight-sided raster, illus trated in FIG. 5. However, the raster has what is commonly referred to as a reverse red trapazoid wherein the red and green traces have opposing slopes with the separation of the green traces at a minimum to the right of the viewing screen 11 as observed by a viewer. Moreover, it was found that convergence of the traces of a color receiver wherein the abovementioned reverse red trapazoid" is present was most difficult, if not impossible, with convergence circuitry normally available in present-day television receivers utilizing triad-gun type cathode ray tubes.
Further, it was found that the inclusion of the flux altering means 23 and 25 in the horizontal deflection windings 19 and 21 and centered about the horizontal axis Hl-l' tended to cause what is classically described as a barrel" effect or overcorrection of the magnetic flux within the toroid deflection yoke 7 of FIG. 1. This barrel effect of the magnetic flux appears as a so-called pin-cushioned" raster (see FIG. 6) as seen by a viewer of the screen 11 of a color cathode ray tube 5. Moreover, such over-correction of the magnetic flux field tended to provide what is known as a forward red trapazoid" wherein the red and green traces have opposing slopes with the separation of the red traces at a minimum to the right of the viewing screen 11. Again, convergence with available apparatus was difficult, if not impossible.
However, it was found that the above-mentioned reverse red trapazoid" effect, due to undercorrection of the magnetic flux field and the forward red trapazoid" effect due to overcorrection of the magnetic flux field, could be virtually eliminated by the proper selection of flux corrective measures. Thus, the employment of the flux altering means 23 and 25 in conjunction with the pairs of added turns 27, 28 and 29, 30
properly spaced therefrom, provide a raster with red and green traces having substantially coincident arcs as illustrated in FIG. 7. Having rendered the slopes of the red and green arcs substantially coincident, it was found that the pincushioned raster is readily correctable by pincushion and convergence circuitry already available in most present day color television receivers.
Thus, the pincushion circuitry readily available in triad-gun type color television receivers is employed, in the usual manner, to effect pincushion correction and convergence of the red and green traces of the electron beams of a color cathode ray tube. Therefore, the toroid deflection yoke 7 is employable with a television receiver having the usual triadgun type cathode ray tube, pincushion correction circuitry and convergence apparatus to provide a desired color image display.
It should perhaps be further noted that the specific embodiment of a toroid-wound deflection yoke illustrated in FIG. 2 includes the added turns 27 and 28 of the first or left horizontal deflection winding 19, as well as the added turns 29 and 30 of the second or right horizontal deflection winding 21. Also, the added turns 27 and 28 are at a slightly different circum ferential spacing from the horizontal axis HH' than the added turns 29 and 30 due to the effect of the earths magnetic field in the Northern Hemisphere.
More specifically, FIGS. 8 and 9 will serve to illustrate the winding distribution of the horizontal deflection windings 19 and 21 in a quadrant to the left and right of the vertical-axis V-V'. Therein, the X-axis represents the angular degrees 6 from the horizontal axis H-H while the Y-axis numerals W represent the rim order intercept of a wire group with respect to the horizontal axis H-H'. Each of the wire groups W is considered to be a unit, three toroid turns in this instance, having a central acting vector unit of force insofar as the magnetic effect and angular degrees are concerned. Moreover, the wire and turn content of each of the wire groups W is varied to provide variations in impedance and may include one or a number of turns depending upon the impedance value desired.
Referring to FIG. 8, the curve is representative of the upper left quadrant as well as the lower left quadrant of the first or left horizontal deflection winding 19 since the winding is substantially symmetrical with respect to the horizontal axis H-H'. This curve of FIG. 8 maybe represented by the following formulation:
Wl=-O.07469+0.42855800.00577166*4-00000682566 0.000000384020d4 wherein =degrees from the horizontal axis 1-1-11 to the center of influence of a wire group W Wl=rim order intercept of a wire group W in the left horizontal deflection winding 19 The upper right quadrant of the second or right horizontal deflection winding 21 is illustrated by the diagram of HO. 9. As mentioned above, the lower right quadrant of the horizontal deflection winding 21 is also represented by the diagram of FIG. 9. In a formulation of the curve:
Wr=0.05 l0l-l 0.43525d O.(),062l4 +0.000076434 0.0000004296 wherein d =degrees from the horizontal axis HH' to the center of in fluence ofa wire group W. Wr=rim order intercept of a wire group W in the right horizontal deflection winding 21.
Additionally, FIG. 10 will serve to illustrate the winding distribution of the vertical deflection windings 31 and 33. Herein, the X-axis represents the angular degrees (1) from the vertical axis V-V' while the Y-axis numerals represent the rim-order intercept of a wire group W with respect to the vertical axis V-V'. As mentioned above, each of the wire groups W represent a central acting vector of force. three toroid turns in this instance, of the vertical windings 31 and 33. H6 10 will serve to represent quadrants to the left and right of the vertical axis V-V', as well as above and below the horizontal axis H-H', since the windings are symmetrical.
As represented by formulation:
Wv=0.11898-l-0.34673d 0.001864145 d =degrees from the vertical axis V-V to the center of influence of a wire group W Wv=rim order intercept of a wire group W in the first and second vertical deflection windings 31 and 33.
It should be noted that toroid-wound deflection yokes have been fabricated wherein both the first and second horizontal deflection windings 19 and 21 and the first and second vertical deflection windings 31 and 33 are symmetrical. In this instance, it has been found that the formulation Wr representa tive of the right horizontal deflection winding 21 is also employed in fabricating the left horizontal deflection winding 19. Moreover, it has been found that satisfactory results have been obtained when the degrees 0 from the horizontal axis H-H' and the degrees d from the vertical axis V-V' to the center of influence of the wire group W are not varied from the above formulations by more than about three degrees (3).
As to the employment of the above-described toroidal deflection yoke, FIG. 11 illustrates a typical television receiver employing the usual antenna 38 whereat transmitted television signals are intercepted and applied to a signal receiver 39. The signal receiver 39 includes the usual RF and IF signal amplifier and detector stages and provides an output signal which is applied via an audio amplifier stage 40 to a loudspeaker 41. Another output from the signal receiver 39 includes signals representative of both luminance and synchronizing information and is applied to a video amplifier stage 43.
One output signal available from the video amplifier stage 43 and representative of luminescence information is applied to a control electrode of a cathode ray tube 45. Another output signal available from the video amplifier stage 43 and representative of synchronizing information is applied to a synchronizing separator stage 47. Therein signals representative of vertical and horizontal scan frequencies are derived and applied to vertical and horizontal deflection stages 49 and 51 respectively.
The vertical deflection stage 49 is coupled via an output transformer 53 to a pair of output terminals YY'- and one of the output terminals Y is AC coupled by a capacitor 54 to a potential reference level such as circuit ground. ln turn, the output terminals YY' are coupled to a pair of series connected vertical deflection coil windings, 55 and 57 associated with a cathode ray tube 45.
In a somewhat similar manner, the horizontal deflection state 51 is coupled to a horizontal output transformer winding 59. One end of the transformer winding 59 is coupled by way of a rectifier stage 61 to a high voltage electrode of the cathode ray tube 45 while the other end of the transformer winding 59 is coupled via a capacitor 68 to a DC potential source 8+. Also, a series connected damper stage 65 and alterable inductor 67, linearity control, shunted by a tuning capacitor are coupled intermediate a junction of the transformer winding 59 and the DC potential source B+.
Further, a pair of series connected horizontal deflection coils 69 and 71 associated with the cathode ray tube 45 have one end thereof connected to a junction 73 of the transformer winding 59 and the other end coupled via the capacitor 63 to the DC potential source 8+ and to the transformer winding 59. Moreover, a capacitor 75 is shunted across the horizontal deflection coil 71 connected to the end of the transformer winding 59 via capacitors 63 and 68 and to the potential source B+.
As can be more readily seen in FIG. 12, a toroidal-wound deflection yoke is schematically illustrated in cooperation with a triad-type color cathode ray tube. Herein, the neck portion 77 of a color cathode ray tube includes the triad of electron guns 79 and is surrounded by the toroid-wound deflection yoke 81.
As observed by a viewer of the screen of a cathode ray tube, the first or left horizontal deflection winding 71 is associated with the beginning of the usual left to right horizontal scanning of the cathode ray tube. This winding 71 is AC coupled by a capacitor 63 to a DC potential source B+. A capacitor 75 shunts the winding 71 and a second or right horizontal deflection winding 69 series connects the first horizontal deflection winding 71 to a horizontal deflection signal source, 73 of FIG. 11. Moreover, a portion of the transformer winding 59 is coupled by the storage boost capacitor 68 to the DC potential source B+.
In a somewhat similar manner, a first or top vertical deflection winding 57 associated with the beginning of vertical scanning is AC coupled by a capacitor 54, to a potential reference level such as circuit ground. The first vertical deflection winding 57 is series connected to a second vertical deflection winding 55 coupled to a vertical deflection signal source Y" ofFlG. 11.
As to the operation of the above-described circuitry illustrated in FIGS. 11 and 12 in conjunction with the toroid deflection yoke 7, it is to be noted that the left or first horizontal deflection winding 71 and the first or top vertical deflection winding 57 are concerned with the start of both horizontal and vertical scanning. Also, the previously mentioned opposing circumferential directions of advancement of the windings serves to effect neutralization of the electrostatic charging of the distributed capacitance between first and second vertical deflection windings 57 and S and the first and second horizontal deflection windings 71 and 69.
Further, the mirror image relationship of the windings assists in neutralizing magnetic and electrostatic cross-induction between the horizontal windings 69 and 71 and the vertical windings 55 and 57. This neutralization of electrostatic and magnetic cross-induction between horizontal and vertical winding is also aided by the substantially sawtooth connection of the vertical windings 57 and 55 as well as the intermittent bank-wound type connections of the horizontal windings 71 and 69.
Additionally, the first horizontal deflection winding 71 most closely associated with the ringing" effect has one end thereof coupled via the capacitor 63 to a potential reference level 8+ with the other end closely associated with the grounded end of the vertical deflection winding 57. Moreover, the horizontal winding 71 and the vertical winding are interleaved which also assists in draining undesired energy from both the horizontal and vertical windings 71 and 57 associated with the start of both horizontal and vertical scan.
Moreover, undesired energy drain of the horizontal deflection winding 71 is even further enhanced by the shunting capacitor 75. Again, the shunting capacitor 75 provides a rapid path for energy drain to the potential reference level 8+.
Thus, it has been found that a viewer is subjected to a minimum of ringing by employment of a circuit arrangement wherein the deflection winding associated with the beginning of electron beam scanning is coupled to a reference level while the winding associated with the end of electron beam scanning is coupled to the signal source. Moreover, the arrangement is inexpensive of parts and of enhanced reliability as a result of the relative simplicity of the structure.
While there has been shown and described what is at present considered the preferred embodiments of the present invention, it will be obvious to those'skilled in the art that various changes and modifications may be made therein without departing from the invention as defined by the appended claims.
We claim: 1. In a color television receiver employing a color cathode ray tube having a plurality of electron beams impinging and scanning a viewing screen and including a potential source and horizontal and vertical signal sources, a deflection circuit arrangement for minimizing ringing currents comprising:
a toroid-wound deflection yoke associated with said color cathode ray tube, said yoke including a core of magnetic material having horizontal and vertical axes with serially connected first and second horizontal deflection windings and serially connected first and second vertical deflection windings, each of said first and second horizontal deflection windings being substantially centered about said horizontal axis and oppositely disposed about said verti cal axis of said core and each of said first and second vertical deflection windings being substantially centered about said vertical axis and oppositely disposed about said horizontal axis of said core with said first and second horizontal and vertical windings circumferentially interleaved;
circuit means coupling said first horizontal deflection winding associated with the start of electron beam scanning of said viewing screen to said potential source;
a capacitor shunting said first horizontal deflection winding;
and
means coupling said second horizontal deflection winding associated with the finish of electron beam scanning of said viewing screen to said horizontaldeflection signal source.
2. The circuit arrangement of claim 1 including means coupling said first vertical deflection winding associated with the start of electron beam scanning of said viewing screen to said potential source and said second vertical deflection winding associated with the finish of electron beam scanning of said viewing screen to said vertical deflection signal source.
3. The circuit arrangement of claim 1 wherein said first and second horizontal deflection windings are in the form of bankwound wire groups.
4. The circuit arrangement of claim 1 wherein said first and second vertical deflection windings each include first and second wire layers electrically connected by a sawtooth-type connection whereby the potential difference intermediate adjacent turns of said first and second layers is substantially constant.
5. The circuit arrangement of claim 1 wherein each of said first and second horizontal deflection windings includes a flux altering means substantially centered about said horizontal axis.
6. The circuit arrangement of claim 1 wherein each of said first and second vertical deflection windings includes a flux-altering means substantially centered about said vertical axis.
7. The circuit arrangement of claim 1 wherein said colored cathode ray tube is of the triad-type having a plurality of electron beams forming a triad configuration,
QETH ECATE o QQEUEM Patent NO. I Dated February 9 (s) CHARLES EDWARD TORSCH and JOSEPH EDWARD THOMAS It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Col. 5, line 54 after "core 16'' insert "and affixing these toroidal wrapped wire turns to the core 16" (This was omitted) Col. 6, line 4 "contracting" should read "contacting" first formula should read: I 2 "Wl= -0.07469 0.4285589 -0.00577l69 3 4 second formula should read: 2 "Wr= 0.05l0l 0.435259 -0.0062l9 +0.0OO0764393 -.000o004296e Col. 8, line 58 "state 51." should read "stage 51" Signed and sealed this 26th day of December 1972.
(SEAL) Attest:
EDWARD"M.FLETC IHER,JR. I 7 ROBERT GOTTSCHALK Attestlng Officer Commissioner of Patents.
a3 mum srirrs PATENT orricr i'liliiiiiiiliiil iii Miiifiililiiiiii Patent No. 396433125 Dated February 15, 1972 Inventor(s) a]...
It: is certified that. error appears in the aboveidentified patent and that said Letters Patent are hereby corrected as shown below:
F C01. 5, line 54 after "core 16" insert and affixing these toroidal Wrapped wire turns to the core 16' (this was omitted) Col. 6, line 4 "eontracting shouldread "contacting Col. 7 lines 56=-57 first formula should read "W1 M00746) 0,.42s55se ---O.OO5771692 O.,00O06825I 53 --.0000003840?@"* 601.. 7 lines 69-73 second formula should read "wr =0..0510i amuse --0.00621a 0.,0o007643e -.0000 0042%ewherein a degrees from the horizontal axis H H to the center of influence of a wire group w. Col. 8, line 59 "state 51" should read "stage 51" This certificate supersedes Certificate of Correction issued Dec. 26 1972 Signed and sealed this 20th day of November 1973.
(SEAL) Attest:
ELM'ARD M. FLETCHERJIL RENE D. TEGTMhYER Arresting Officer Acting Commissioner of Patents Pod-05o UNITED STATES PATENT OFFICE 5 CERTIFICATE OF COREUNON Patent No. 3 125 Dated February 5 1972 fls) CHARLES EDWARD TORSCH and JOSEPH EDWARD THOMAS It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Col. 5, line 54 after "core 16" insert "and affixing these toroidal Wrapped Wire turns to the core 16'' (This was omitted) Col. 6, line 4 "contracting" should read "contacting" first formula should read: 2 "Wl= -0.07469 0.4285589 -0.00577l69 +0.00OO682569 -.OQOOOO384O29 +0.0OO0764393 .0O00OO429694 Col. 8, line 58 "state 51," should read "stage 51" Signed and sealed this 26th day of December 1972.
(SEAL) Attest:
EDWARD' M.FLETQHER,JR. ROBERT GOTTSCHALK Attesclng Officer Commissioner of Patents

Claims (7)

1. In a color television receiver employing a color cathode ray tube having a plurality of electron beams impinging aNd scanning a viewing screen and including a potential source and horizontal and vertical signal sources, a deflection circuit arrangement for minimizing ringing currents comprising: a toroid-wound deflection yoke associated with said color cathode ray tube, said yoke including a core of magnetic material having horizontal and vertical axes with serially connected first and second horizontal deflection windings and serially connected first and second vertical deflection windings, each of said first and second horizontal deflection windings being substantially centered about said horizontal axis and oppositely disposed about said vertical axis of said core and each of said first and second vertical deflection windings being substantially centered about said vertical axis and oppositely disposed about said horizontal axis of said core with said first and second horizontal and vertical windings circumferentially interleaved; circuit means coupling said first horizontal deflection winding associated with the start of electron beam scanning of said viewing screen to said potential source; a capacitor shunting said first horizontal deflection winding; and means coupling said second horizontal deflection winding associated with the finish of electron beam scanning of said viewing screen to said horizontal deflection signal source.
2. The circuit arrangement of claim 1 including means coupling said first vertical deflection winding associated with the start of electron beam scanning of said viewing screen to said potential source and said second vertical deflection winding associated with the finish of electron beam scanning of said viewing screen to said vertical deflection signal source.
3. The circuit arrangement of claim 1 wherein said first and second horizontal deflection windings are in the form of bank-wound wire groups.
4. The circuit arrangement of claim 1 wherein said first and second vertical deflection windings each include first and second wire layers electrically connected by a sawtooth-type connection whereby the potential difference intermediate adjacent turns of said first and second layers is substantially constant.
5. The circuit arrangement of claim 1 wherein each of said first and second horizontal deflection windings includes a flux altering means substantially centered about said horizontal axis.
6. The circuit arrangement of claim 1 wherein each of said first and second vertical deflection windings includes a flux-altering means substantially centered about said vertical axis.
7. The circuit arrangement of claim 1 wherein said colored cathode ray tube is of the triad-type having a plurality of electron beams forming a triad configuration.
US841935A 1969-07-15 1969-07-15 Deflection system for triad-beam cathode-ray tube utilizing a toroid-type deflection yoke Expired - Lifetime US3643125A (en)

Applications Claiming Priority (3)

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US84189369A 1969-07-15 1969-07-15
US84193569A 1969-07-15 1969-07-15
US84178269A 1969-07-15 1969-07-15

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US841782A Expired - Lifetime US3631902A (en) 1969-07-15 1969-07-15 Deflection system for triad-beam cathode-ray tube

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BE (1) BE753426A (en)
CA (2) CA961543A (en)
DE (2) DE2035082A1 (en)
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GB (3) GB1324412A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4511871A (en) * 1983-07-18 1985-04-16 Rca Corporation Modified deflection yoke coils having shootback windings

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4151497A (en) * 1976-04-05 1979-04-24 Gte Sylvania Incorporated Arc-resistant deflection yoke
US5530251A (en) * 1994-12-21 1996-06-25 International Business Machines Corporation Inductively coupled dual-stage magnetic deflection yoke

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US2293147A (en) * 1935-03-26 1942-08-18 Rca Corp Television system
US2644103A (en) * 1951-12-11 1953-06-30 Motorola Inc Television deflection system
US2925542A (en) * 1957-05-31 1960-02-16 Gen Electric Deflection and dynamic convergence system for multi-beam cathode ray tubes
US3319112A (en) * 1964-02-10 1967-05-09 Rca Corp Linearity correction circuit
US3329859A (en) * 1964-08-31 1967-07-04 Rca Corp Pincushion correction circuit having saturable reactor and means for adjusting the phase and magnitude of the horizontal component

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US2414925A (en) * 1944-01-26 1947-01-28 Farnsworth Television & Radio Scanning and focusing yoke

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2293147A (en) * 1935-03-26 1942-08-18 Rca Corp Television system
US2644103A (en) * 1951-12-11 1953-06-30 Motorola Inc Television deflection system
US2925542A (en) * 1957-05-31 1960-02-16 Gen Electric Deflection and dynamic convergence system for multi-beam cathode ray tubes
US3319112A (en) * 1964-02-10 1967-05-09 Rca Corp Linearity correction circuit
US3319111A (en) * 1964-02-10 1967-05-09 Rca Corp Linearity correction circuit
US3329859A (en) * 1964-08-31 1967-07-04 Rca Corp Pincushion correction circuit having saturable reactor and means for adjusting the phase and magnitude of the horizontal component

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4511871A (en) * 1983-07-18 1985-04-16 Rca Corporation Modified deflection yoke coils having shootback windings

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FR2051764A1 (en) 1971-04-09
DE7026618U (en) 1971-02-18
US3631902A (en) 1972-01-04
GB1324413A (en) 1973-07-25
GB1324414A (en) 1973-07-25
CA961543A (en) 1975-01-21
BE753426A (en) 1971-01-14
FR2051764B1 (en) 1973-04-27
CA945267A (en) 1974-04-09
GB1324412A (en) 1973-07-25
DE2035082A1 (en) 1971-02-04

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Effective date: 19810708